Insulator for electric-railway cars.



J. CHRISTENSEN. INSULATORFOR ELECTRIC RAILWAY CARS.

Patented Aug. 15, 1911.

APPLICATION FILED SEPT. 27, 1910.

ZWMAJ;

- UNITED STATES PATENT OFFICE.

JOHN CHRISTENSEN, 6F EVANS CITY, PENNSYLVANIA.

INSULATOR FOR ELECTRIC-RAILWAY CARS.

ence being bad to the accompanying drawings, which form part of this specification.

-This invention is an improvement in devices for insulating and suspending electrical appliances, and is particularly de- "signed for use on electric railway cars to suspend rheostats, and other electrical apparatus, from the car body or truck.

The chief'objections to the present known insulators used for such purposes are their tendency to absorb moisture, their liability to breakage, their comparatively high con ductivity when broken, or when possessing cracks or'flaws in the non-conducting material, andthe leakage of current.which they permit between the suspended apparatus and the supporting structure.

The primary object of the present invention is to obviate the troubles which have been heretofore experienced in insulating rheos'tats, or resistance boxes, and other electrical apparatus, used in connection with the equipment of electric railway cars, and which are usually located under the body of the car, and exposed to the weather, and to water splashed or thrown upward by the Wheels, or running down from i the car frame; and which is apt to leak into the interstices between the suspended apparatus and the supporting structure, and short circuit the electric current.

The invention in brief consists in an insulating suspending device, comprising a body of insulating material surroundingthe bolt used to connect the suspended apparatus to the supportingstructure. The upper part of such insulating material is inclosed in a metal lic. protecting jacket, which projects through the supporting structure into a spacer or insulating body of porcelain, glass or earthenware. which is interposed between the supporting structure and the suspended apparatus, and by which moisture and foreign substances are excluded entirely from the bolt, so that no current can leak from the connecting bolt to the supporting structure. Such an insulated hanger gives the highest "possible resistance to leakage of current, is

Specification of Letters Patent.

Application filed September 27, 1910.

Patented Aug. 15, 1911.

Serial No. 584,071.

both light and durable, contains tllP'DltlXimum of insulating effect with a minimum ofmaterial. is structurally strong. and entirely prevents any possible diversion of current from the electrified body attached to it.

I will now describe the invention with reference to the accompanying drawings, in which I have illustrated the invention as embodied in devices used for suspending a rheostat from a car body or truck.

Figure 1 represents an enlarged section of one of the insulating hangers. Fig. 2 represents a side elevation of a rheostat or resistance box suspended by my novel de vices. Fig. 3 represents an end elevation of Fig. 2.

The rheostat or resistance box 1 may be of any desired construction. an ordinary type being shown in the drawings. said box is provided with plates or end walls 1. which are connected by tie rods 1 and 1. Grids 2. which constitute the. resistance for the circuit. are supported by the rods 1 from which they are insulated in the usual manner. The end walls 1 are provided with outwardly projecting lugs or members 1 by which the box or rheostat may be hung from the car body or supporting structure, conventionally indicated at 10. The rheost-at is ordinarily suspended from the supporting structure at four points. and I use four insulated suspending devices or hangers to suspend the rheostat from the-support or car body. Each insulated hanger is preferably constructed as follows, see Fig. 1.

I interpose. between the supporting structure 10 and the suspended rheostat or afpparatus 1, an insulating spacer body 3 which is made out of non-conducting, non-absorbent insulating material, such as glass, earthenware or porcelain and which has a dripping lip 33*. The shape of this insulator or spacer 3 is such as to give it the most pos sible creepage surface without decreasing the mechanical strength of same. This insulator 3 surrounds a bolt 4 the lower end of which passes through an opening in the flange l of the rheostat end wall, and is secured thereto by a nut- P and interposed washer 4 The upper end or head 4 of bolt 4 is seated in a cavity in an insulator block or body 5 of'tough fibrous insulating non-absorbing material, the cavity being of such shape as to prevent the bolt turning when its head is inserted therein. The

rests nJon a flange 10" on the suioortin k D structure 10 attached to the ear frame or.

body from which the'i'heostat is to be suspended.

The bolt l is effectually insulated from the part 10 by means of a bushing 7 made out f of non-conductive non-absorbent insulating material which has a flange 7 on its upper end fitted within the casing ti underneath I the block 5; and said bushing t extends down around the bolt 4 through insulator;

3 and effectually insulates the bolt from the casing 6 and the part 10 The casing (3 preferably has a cylindric extension (3 on its lower end which surrounds the upper part of the bushing 7 below flange 7 and extends through the opening inthe part 10 and slightly into the bore of the insulator 3, see Fig. 1. The object of the extension 6". of the protecting casing (S is to prevent cutting of the bushing 7 bythe vibration of the rheostat, .or chafing against part, 10.

Between the bottom of the casing 'Gand the supporting structure 10 is an insulating washer 8 which prevents moisture or any; foreign substances from coming in contact with the interior of the insulator.

Between the spacer or insulator 3 and the supporting structure 10 and between the insulator 3.and the suspended apparatus 1. are placed washers 8 and 8"; said washers 8, 8, 8 are made of elastic non-conductive, non-ahsorbent material, to prevent moisture from getting into contact with bolt at, and to relieve the compression contact pressure on insulator 3.

After the head of connecting bolt t is insertcd in insulator 5 within protecting casing fi, the whole is thoroughly boiled in a non-conductive, non-absorbent con'ipound, such as paraflin, and the cavity in block 5 is filled with same, as indicated at 5 to prevent the bolt head 4. from making-contact with metal cap 6? which is then securely soldered to protecting casing 6.

' Tnsulatmg suspending devices thus constructed will effectually prevent moisture or any foreign substances coming into contact with the bolt 4-, which is surrounded by the non-condnctive bodies 7 and 3, and 7 and and moisture is prevented from getting to the head of the bolt by the filling 5 and .the flange 7 on the upper end of the bushing 7 which extends into the lowe end of the protecting casing t3.

The upper section of my insulator is a body of non-conductivc, non-absorbent tough fibrous material, surroumling the bolt: l rad, and having the cavity in its upper end receiving the bolt head, filled with a nonconductive, n0n-absorbent compound; said body; of'insulating material resting on the casing 6 ,'and is in turn protected by the casing (5 and tive, non-absorbent material, which bushing surrounds the bolt to its threaded lower end the insulating spacer" o.

The upper section" of my insulating hanger inclosed in a metallic protecting casing whichextemls'down through tl supporting structure, and enters theinsulating body or siacer 3 interposed between the suspended apparatus and the 'isnpporting 'ructure; the extended portion of the easabrasion against the supports. or otherwise. The distance the said extended portion of the casing enters said spacer or insulator. depends on the size of the latter, but should not exceed one-fifth the height of said insulator, in order to maintain sufficient creepage surface, or separation, between said protecting casing and the suspended apparatus.

What I claim is: v i

1. An insulating suspending device comprising a casing. a bolt having its head confined in said casing and its body projecting therefrom, an insulating bushing surrounding the exterior portion of the bolt and extending into the casing and having a flange on its end within the casing, an insulating body in the casing surrounding the head of the bolt and resting upon the bushing flange, 'and an insulating spacer on said bushing outside the casing, substantially as described. V Y

- 2. An insulating suspending device, comprising a casing,- a bolt having its head in the casing and its shank projecting therefrom, an insulating bushing surrounding the shank of the bolt below the casing and extending thereinto and having a. flange on its upper end within the casing, an insulating block in the casing surrounding the head of the bolt and resting on the flange of the bushing. and having a recess for the reccption of the bolt head, a non-conductive moisture proof substance filling said recess, and an insulating spacer body strung on said bushing and bolt; below the casing, and between the latter and the suspended device.

3. In combination with a supporting structure'aml an electrical apparatus adapted to be suspended lhcref'ron'i; of an insulated suspending device comprising a casing mounted on said supporting structure, and having a cylindric extension depending through the supporting structure, a bolt having its head confined in said casing and its shank depending therefrom and extending through said structure, an insulating bushing surrounding the shank of. the bol and extending through the cylindric extension of the casing, an'insulating block in the casing surrounding the head of the bolt above the bushing, and an insulating spacer t flange of a bushing 7 made of n0n-conducmg protecting the-b'ushing from injury by body strung on said bushing and bolt below the casing, and interposed between the supporting structure and the suspended apparatus.

4. In combination with a supporting structure and an electrical apparatus adapted to be suspended therefrom; of an in-' sulated suspending device comprising a 1116- tallic casing mounted upon said structure and having a eylindric extension depending through an opening in the supporting structure, a bolt having its head confined in said asing and its shank extending therethrough and depending below said structure, an insulating bushing surrounding the shank of the bolt and extending through the opening in the supporting structure into the casing and having a flange on its upper end in the JOHN CHRISTENSEN.-

\Vitnesses J. ZEMAN, Issnon L. ZEMAN. 

